1. Field of the Invention
The present invention relates to a steering device for a marine drive, and in particular to a restraining mechanism for the steering device used in conjunction with a marine drive.
2. Description of the Related Art
Many watercraft employ outboard motors that are mounted on the aft end of the watercraft. An outboard motor generally includes a power head that houses an engine, a drive shaft housing situated below the power head, and a lower unit that is positioned below the drive shaft housing. The lower unit typically houses a transmission and a propulsion shaft that drives a propulsion device, such as a propeller.
As is well-known in the art, outboard motors include a clamping bracket which secures the outboard motor to a transom of a watercraft. A swivel bracket is pivotally secured to the clamping bracket so as to allow both steering movement of the motor about a steering axis and trimming and tilting movement of the motor about a tilt and trim axis. The trimming movement relative to the watercraft transom is often required to adjust the angular orientation of a thrust vector associated with a propeller. In particular, by adjusting the trim position of the outboard motor, an optimum orientation of the thrust vector can be obtained.
A tiller or steering arm is attached to the outboard motor to facilitate steering movement. In many instances, it is desirable to mechanically maintain a predetermined tack of the watercraft so that the operator is not required to continually have a hand on the tiller. For example, when the operator is trolling for fish, he or she may want to keep both hands free while the watercraft continues a straight-ahead or circular tack. Similarly, when traveling in a straight line across a current, it is necessary to position the motor to steer slightly into the current to compensate for the forces of the current that tend to turn or propel the watercraft in an undesired direction. Thus, it is desired to have a tiller position-locking device that is capable of maintaining the steering components in any of a continuous array of positions.
Current tiller locks generally incorporate a semi-circular shaped friction plate to track the movement of the tiller. The semi-circular friction plates are rigidly attached to the outboard motor, and project into an inner space in the hull across the entire width of the stern. With friction plates increasing in size, the amount of inner hull space occupied by the tiller locks are also increasing.
What is needed is a steering locking device that is capable of maintaining the desired heading of the watercraft, yet not occupy a large amount of space in the inner hull. Further, the locking device should be easily engaged or disengaged as desired.